Читать книгу Respiratory Medicine - Stephen J. Bourke - Страница 65

Percussion over normal air‐filled lung produces a resonant note, whereas percussion over solid organs, such as the liver or heart, produces a dull note. The percussion note over an area of consolidation is dull; over an effusion, the note is particularly dull (‘stony dull’). Hyperresonance may be present in emphysema or over the area of a pneumothorax, although it is rarely a reliable sign. Percussion technique is important and requires practice. The resting finger should be placed flat against the chest wall in an intercostal space (tip: focus on getting the middle phalanx, rather than the whole finger, flat against the chest). The percussing finger should strike the dorsal surface of the middle phalanx and should be lifted clear after each percussion stroke. All areas should be percussed. The order should allow immediate comparison of one area with the equivalent area on the opposite side. To recognise a particular note as hyperresonant takes years of practice and a well‐tuned ear. To pick up a difference between one side and the other is significantly easier. Remember why we have two lungs! When percussing the back of the chest, it is helpful to ask the patient to cross their arms over in front of them, such that one elbow is placed on top of the other. This brings the scapulae forward and out of the way.